Heraclitus, fr. 56 D.-K.
ἐξηπάτενται, φησίν, οἱ ἄνθρωποι πρὸς τὴν γνῶσιν τῶν φανερῶν παραπλησίως Ὁμήρωι, ὃς ἐγένετο τῶν Ἑλλήνων σοφώτερος πάντων. ἐκεῖνόν τε γὰρ παῖδες φθεῖρας κατακτεῖνοντες ἐξηπάτησαν εἰπόντες· ὅσα εἴδομεν καὶ ἐλάβομεν, ταῦτα ἀπολείπομεν, ὅσα δὲ οὔτε εἴδομεν οὔτ’ ἐλάβομεν, ταῦτα φέρομεν.
Humans, he says, fool themselves concerning knowledge of what is evident; like Homer, who was wiser than all other Greeks. For indeed some boys who were killing lice fooled him by saying: “What we saw and caught, we leave behind; what we did not see or catch, we carry with us”.